leetcode36. Valid Sudoku

Determine if a Sudoku is valid, according to: Sudoku Puzzles - The Rules.

The Sudoku board could be partially filled, where empty cells are filled with the character '.'.

题目意思就是判断是否符合数独的要求，即行内无重复，列内无重复，九个小的正方形也没有重复。

class Solution {
public:
    bool isValidSudoku(vector<vector<char>>& board) {
        int validRow[9][9] = {0},validCol[9][9] = {0}, validSu[9][9] = {0};
        
        for( int i = 0; i < board.size() ; ++i)
        {
            for( int j = 0; j < board[i].size() ; ++j)
            {
                if( board[i][j] != '.')
                {
                    int num = board[i][j] - '0' -1;
                    int k = i/3 *3 +j/3;
                    if(validRow[i][num] || validCol[j][num]||validSu[k][num])
                        return false;
                    else
                        validRow[i][num] = validCol[j][num] = validSu[k][num] = 1;
                }
            }
        }
        return true;
       
    }
};